Publicans have urged Irish Water not to impose restrictions coming into the weekend amid fears it will affect the night-time economy.

The Licensed Vintners Association said it was "very concerned" that cut-offs would affect the ability of its 600 members to remain open from Thursday, when opening hours are extended.

"We're very concerned about the potential affect on pubs and the wider night-time economy," CEO Donall O'Keeffe said.

"The trade is not too busy Monday, Tuesday and Wednesday and we think most pubs will get through.

"For Thursday and into the weekend, closing times are later. The late bar scene will need water until 3am for clean-up.

"We think (Irish Water) should review those restrictions over the weekend in particular."

Restrictions were introduced across Dublin and Co Wicklow last night, affecting 40pc of properties and around 500,000 customers. They will remain in place all this week from 10pm to 5am as part of efforts to replenish water stores.

Guinness said it did not expect restrictions to affect supply as it had reduced water consumption by 31pc over recent years and had developed a well and treatment plant at the brewery which meant it was "less reliant" on the public supply and kept a "significant" amount in storage.

The Restaurants Association of Ireland has also raised concerns, and has urged the utility to provide water tankers in the event of cut-offs.

Restaurateur Kevin O'Toole from Chameleon in Temple Bar, said a 10pm cut-off time was "ridiculous".

"We don't know how it's going to affect us. A 10pm cut-off is ridiculous. It's a requirement to have clean running water in a food business. We need a bit of consideration and compassion. You can't let one sector suffer."

Some 39 supplies are currently under restriction across 12 counties. Irish Water said it did not expect to have supply issues which would require tankers to be deployed, but said any customer with issues should make contact on 1850 278 278. The Irish Hotels Federation said the majority of hotels would not be affected as most had 48 hours' worth stored on site.